The present invention relates to a silicone-based adhesive sheet, a method for manufacturing same, and a semiconductor device. More particularly, this invention relates to a silicone-based adhesive sheet that is easier to handle and provides superior adhesion, to a method for efficiently manufacturing this silicone-based adhesive sheet, and to a semiconductor device with superior reliability, wherein a semiconductor chip is bonded to a chip attachment component by means of this silicone-based adhesive sheet.
Silicone-based adhesives have been used to bond semiconductor chips to chip attachment components. Examples of these silicone-based adhesives include curable silicone compositions in the form of a liquid or paste comprising at least of an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule, and a hydrosilylation reaction catalyst. Another example is a curable silicone composition in the form of a liquid or paste further containing, as an adhesion promoter, an organopolysiloxane having at least one silicon-bonded alkenyl group or silicon atom-bonded hydrogen atom and at least one silicon-bonded alkoxy group per molecule (see Japanese Laid-Open Patent Application 3-157474).
However, a problem with a curable silicone composition in the form of a liquid or paste is that a low-viscosity silicone oil or the like tends to ooze out of the composition during curing and foul the surrounding area. This low-viscosity silicone oil might be an organopolysiloxane with a low degree of polymerization included in the main organopolysiloxane component, or it might be an organopolysiloxane with a low degree of polymerization included in the organopolysiloxane added as an adhesion promoter, which makes it extremely difficult to eliminate these oils completely. Consequently, a drawback to a curable silicone composition in the form of a liquid or paste is that it is difficult to handle.
Another problem is that when a curable silicone composition such as the above is used to bond a semiconductor chip to a chip attachment component, and a bonding wire or beam lead is then bonded to a bonding pad on the chip, there is a decrease in wire bondability, which compromises the reliability of the semiconductor device thus obtained.
In an effort to solve these problems, there has been a proposal for a silicone-based adhesive sheet produced by coating one or both sides of a silicone rubber sheet with a curable silicone composition in the form of a liquid or paste (see Japanese Laid-Open Patent Application 10-112516), but even this does not solve the above problems sufficiently.
An object of the present invention is to provide a silicone-based adhesive sheet that is easier to handle and affords superior adhesion, a method for efficiently manufacturing this silicone-based adhesive sheet, and a semiconductor device with superior reliability, wherein a semiconductor chip is bonded to a chip attachment component by means of this silicone-based adhesive sheet.
The present invention is directed to a silicone-based adhesive sheet produced by curing a silicone composition between backing materials that do not stick to the cured product of the composition, wherein at least one of the backing materials has oxygen atoms and/or sulfur atoms in contact with the composition.
The present invention is also directed to a method of manufacturing a silicone-based adhesive sheet, the method comprising curing a silicone composition between backing materials that do not stick to the cured product of the composition, wherein at least one of the backing materials has oxygen atoms and/or sulfur atoms in contact with the composition.
The present invention is further directed to a semiconductor device comprising a semiconductor chip, a chip attachment component, and the aforementioned silicone-based adhesive, wherein the semiconductor chip is bonded to the chip attachment component with the silicone-based adhesive sheet.